| 摘要 |
PROBLEM TO BE SOLVED: To reduce sputtering particles adhering to weld beads and steel plate surface, while giving excellent welding workability in all positions, and to improve high temperature crack resistance of an initial pass of one-side joint welding.SOLUTION: In a flux-cored wire for gas shielded arc welding, the content of C in the outer skin made of steel is ≤0.02 mass% of the total mass of the whole outer skin. A flux in mass% to the total mass of the wire contains: 5.0-6.5% TiO, 0.5-0.8% SiO, 0.3-0.6% ZrO, 0.1-0.3% AlO, 0.10-0.20% of the total value in terms of Na2O value and K2O value, and not less than 2.0 of in terms of K2O value/Na2O value, 0.02-0.10% in terms of F value, 0.1-0.3% Mg. In the total amount of the outer skin made of steel and the flux, 0.03-0.06% C, 0.3-0.6% Si, 2.5-3.5% Mn, and 0.4-0.8% Al are contained, and Al is added at 0.1% or more from the flux in the form of Fe-Al. |
